The present invention relates generally to escape devices, and more particularly relates to escape devices for high-rise buildings.
In case of emergencies such as fire in tall apartment buildings, hotels, office buildings and the like, conventional means of escape such as stairs and ladders may be impractical or impossible to use. This invention relates to an apparatus which permits an object, usually a person, to be lowered from an elevated place in such a building at a controlled and safe rate of descent.
Prior controlled descent devices, such as that disclosed in Devine, U.S. Pat. No. 4,653,609, the disclosure of which is hereby incorporated by reference in its entirety, may be mounted to the interior of a building, and can lower persons along the exterior of the building at a controlled rate for safe descent. While such systems have enjoyed much success, there are some drawbacks. For example, the apparatuses are generally very large and heavy. This bulk makes transporting the apparatus difficult, especially mounting the apparatus to a building""s interior walls. Similarly, the walls must have the strength and load bearing capacity to support the descent apparatus off the ground. These descent apparatuses also typically require the user to manually manipulate the arm so that it extends through an opening in the building for egress.
Many descent apparatuses also include a backup braking system in the event the main system fails. Unfortunately, the transition between the main system and the backup system is not very smooth, and can be uncomfortable to the user of the device. During transition, the rate of descent can quickly increase or decrease as the back-up system takes over, resulting in a jerky transition that does not provide a smooth descent for the user or object.
In light of the foregoing, the general object of the invention is to provide a novel controlled descent apparatus that is light weight and compact.
It is also an object of the present invention to provide a descent apparatus having and arm for guiding the cable to the exterior of a building for descent, the arm being self-deploying.
It is a further object of the present invention to provide a descent apparatus having smooth and safe transition between the main braking system and the backup braking system.
In accordance with these objects, the present invention provides a novel descent apparatus comprising a frame adapted to be mounted to building adjacent an opening in the wall, and an arm rotatable between a stored position generally within the frame and an active position projecting a free end through the opening in the wall. A supply of cable is stored on a spool rotatably connected to the frame, the cable guided to a pulley proximate the free end of the arm whereby a weight attached to the cable beyond the pulley will descend while drawing cable from the supply. A hydraulic circuit is operatively connected to the spool to control the rate at which the cable is drawn from the supply.
According to an aspect of the present invention to construct the apparatus is constructed in a compact nature to reduce the size and weight, thus making mobility and mounting easier. Preferably, the hydraulic circuit includes a positive displacement pump mounted on the frame, a first reservoir connected to a pump inlet and a second reservoir connected to a pump outlet, a flow control valve connected to the pump outlet to limit flow of fluid through the outlet to a preselected rate. Preferably, the first and second reservoirs are integrally formed with the frame to provide a lightweight and compact apparatus. Most preferably, third and second reservoirs are associated with a second hydraulic circuit and are also integrally formed with the frame. Preferably, the frame and arm are constructed of aluminum. It has been found the aluminum has sufficient strength characteristics for supporting the apparatus and any weight placed on the end of the cable, such as a person. Furthermore, aluminum is significantly lighter than previously used metals, allowing the compact apparatus to be more easily moved and mounted.
According to another aspect of the invention, the arm is self-deploying, wherein the arm moves from an inactive position to an active position under its own weight. Preferably, the arm includes an inner section and an outer section, and a first bushing pivotally connects the outer section to the inner section. A second bushing pivotally connects the inner section to the frame, and the outer section rotates about the first bushing faster than the inner section rotates about the second bushing as the arm rotates from the stored position to the active position. This provides a self-deploying arm which quickly and easily moves from a stored position to an active position.
According to yet another aspect of the invention, a second hydraulic circuit is operatively connected to the spool and includes a second positive displacement pump mounted on the frame, a third reservoir connected to a pump inlet and a fourth reservoir connected to a pump outlet, a second flow control valve connected to the pump outlet to limit flow of fluid through the second hydraulic circuit to a rate either identical to or slightly higher than the first hydraulic circuit to control the rate at which the cable is drawn from the supply when the spool turns at a speed faster than permitted by the first hydraulic circuit. The first and second hydraulic circuits are closely regulated to provide a smooth and preferably immediate transition between the transfer of control from one circuit to the other.